diff options
author | Florian Westphal <fw@strlen.de> | 2014-06-10 23:12:56 +0200 |
---|---|---|
committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2014-06-25 19:15:38 +0200 |
commit | 9500507c61381ceda4edbefa7361a4d26f54eb17 (patch) | |
tree | ae02c076af642052494bcc4f97bfa855ccb17498 /net/netfilter | |
parent | f6b50824f7d85f72285c17fec66076a36907089f (diff) | |
download | linux-9500507c61381ceda4edbefa7361a4d26f54eb17.tar.bz2 |
netfilter: conntrack: remove timer from ecache extension
This brings the (per-conntrack) ecache extension back to 24 bytes in size
(was 152 byte on x86_64 with lockdep on).
When event delivery fails, re-delivery is attempted via work queue.
Redelivery is attempted at least every 0.1 seconds, but can happen
more frequently if userspace is not congested.
The nf_ct_release_dying_list() function is removed.
With this patch, ownership of the to-be-redelivered conntracks
(on-dying-list-with-DYING-bit not yet set) is with the work queue,
which will release the references once event is out.
Joint work with Pablo Neira Ayuso.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter')
-rw-r--r-- | net/netfilter/nf_conntrack_core.c | 68 | ||||
-rw-r--r-- | net/netfilter/nf_conntrack_ecache.c | 96 |
2 files changed, 95 insertions, 69 deletions
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 1f4f954c4b47..de88c4ab5146 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -352,40 +352,6 @@ static void nf_ct_delete_from_lists(struct nf_conn *ct) local_bh_enable(); } -static void death_by_event(unsigned long ul_conntrack) -{ - struct nf_conn *ct = (void *)ul_conntrack; - struct net *net = nf_ct_net(ct); - struct nf_conntrack_ecache *ecache = nf_ct_ecache_find(ct); - - BUG_ON(ecache == NULL); - - if (nf_conntrack_event(IPCT_DESTROY, ct) < 0) { - /* bad luck, let's retry again */ - ecache->timeout.expires = jiffies + - (prandom_u32() % net->ct.sysctl_events_retry_timeout); - add_timer(&ecache->timeout); - return; - } - /* we've got the event delivered, now it's dying */ - set_bit(IPS_DYING_BIT, &ct->status); - nf_ct_put(ct); -} - -static void nf_ct_dying_timeout(struct nf_conn *ct) -{ - struct net *net = nf_ct_net(ct); - struct nf_conntrack_ecache *ecache = nf_ct_ecache_find(ct); - - BUG_ON(ecache == NULL); - - /* set a new timer to retry event delivery */ - setup_timer(&ecache->timeout, death_by_event, (unsigned long)ct); - ecache->timeout.expires = jiffies + - (prandom_u32() % net->ct.sysctl_events_retry_timeout); - add_timer(&ecache->timeout); -} - bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report) { struct nf_conn_tstamp *tstamp; @@ -394,15 +360,20 @@ bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report) if (tstamp && tstamp->stop == 0) tstamp->stop = ktime_to_ns(ktime_get_real()); - if (!nf_ct_is_dying(ct) && - unlikely(nf_conntrack_event_report(IPCT_DESTROY, ct, - portid, report) < 0)) { + if (nf_ct_is_dying(ct)) + goto delete; + + if (nf_conntrack_event_report(IPCT_DESTROY, ct, + portid, report) < 0) { /* destroy event was not delivered */ nf_ct_delete_from_lists(ct); - nf_ct_dying_timeout(ct); + nf_conntrack_ecache_delayed_work(nf_ct_net(ct)); return false; } + + nf_conntrack_ecache_work(nf_ct_net(ct)); set_bit(IPS_DYING_BIT, &ct->status); + delete: nf_ct_delete_from_lists(ct); nf_ct_put(ct); return true; @@ -1464,26 +1435,6 @@ void nf_conntrack_flush_report(struct net *net, u32 portid, int report) } EXPORT_SYMBOL_GPL(nf_conntrack_flush_report); -static void nf_ct_release_dying_list(struct net *net) -{ - struct nf_conntrack_tuple_hash *h; - struct nf_conn *ct; - struct hlist_nulls_node *n; - int cpu; - - for_each_possible_cpu(cpu) { - struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu); - - spin_lock_bh(&pcpu->lock); - hlist_nulls_for_each_entry(h, n, &pcpu->dying, hnnode) { - ct = nf_ct_tuplehash_to_ctrack(h); - /* never fails to remove them, no listeners at this point */ - nf_ct_kill(ct); - } - spin_unlock_bh(&pcpu->lock); - } -} - static int untrack_refs(void) { int cnt = 0, cpu; @@ -1548,7 +1499,6 @@ i_see_dead_people: busy = 0; list_for_each_entry(net, net_exit_list, exit_list) { nf_ct_iterate_cleanup(net, kill_all, NULL, 0, 0); - nf_ct_release_dying_list(net); if (atomic_read(&net->ct.count) != 0) busy = 1; } diff --git a/net/netfilter/nf_conntrack_ecache.c b/net/netfilter/nf_conntrack_ecache.c index 1df176146567..4e78c57b818f 100644 --- a/net/netfilter/nf_conntrack_ecache.c +++ b/net/netfilter/nf_conntrack_ecache.c @@ -29,6 +29,90 @@ static DEFINE_MUTEX(nf_ct_ecache_mutex); +#define ECACHE_RETRY_WAIT (HZ/10) + +enum retry_state { + STATE_CONGESTED, + STATE_RESTART, + STATE_DONE, +}; + +static enum retry_state ecache_work_evict_list(struct ct_pcpu *pcpu) +{ + struct nf_conn *refs[16]; + struct nf_conntrack_tuple_hash *h; + struct hlist_nulls_node *n; + unsigned int evicted = 0; + enum retry_state ret = STATE_DONE; + + spin_lock(&pcpu->lock); + + hlist_nulls_for_each_entry(h, n, &pcpu->dying, hnnode) { + struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h); + + if (nf_ct_is_dying(ct)) + continue; + + if (nf_conntrack_event(IPCT_DESTROY, ct)) { + ret = STATE_CONGESTED; + break; + } + + /* we've got the event delivered, now it's dying */ + set_bit(IPS_DYING_BIT, &ct->status); + refs[evicted] = ct; + + if (++evicted >= ARRAY_SIZE(refs)) { + ret = STATE_RESTART; + break; + } + } + + spin_unlock(&pcpu->lock); + + /* can't _put while holding lock */ + while (evicted) + nf_ct_put(refs[--evicted]); + + return ret; +} + +static void ecache_work(struct work_struct *work) +{ + struct netns_ct *ctnet = + container_of(work, struct netns_ct, ecache_dwork.work); + int cpu, delay = -1; + struct ct_pcpu *pcpu; + + local_bh_disable(); + + for_each_possible_cpu(cpu) { + enum retry_state ret; + + pcpu = per_cpu_ptr(ctnet->pcpu_lists, cpu); + + ret = ecache_work_evict_list(pcpu); + + switch (ret) { + case STATE_CONGESTED: + delay = ECACHE_RETRY_WAIT; + goto out; + case STATE_RESTART: + delay = 0; + break; + case STATE_DONE: + break; + } + } + + out: + local_bh_enable(); + + ctnet->ecache_dwork_pending = delay > 0; + if (delay >= 0) + schedule_delayed_work(&ctnet->ecache_dwork, delay); +} + /* deliver cached events and clear cache entry - must be called with locally * disabled softirqs */ void nf_ct_deliver_cached_events(struct nf_conn *ct) @@ -157,7 +241,6 @@ EXPORT_SYMBOL_GPL(nf_ct_expect_unregister_notifier); #define NF_CT_EVENTS_DEFAULT 1 static int nf_ct_events __read_mostly = NF_CT_EVENTS_DEFAULT; -static int nf_ct_events_retry_timeout __read_mostly = 15*HZ; #ifdef CONFIG_SYSCTL static struct ctl_table event_sysctl_table[] = { @@ -168,13 +251,6 @@ static struct ctl_table event_sysctl_table[] = { .mode = 0644, .proc_handler = proc_dointvec, }, - { - .procname = "nf_conntrack_events_retry_timeout", - .data = &init_net.ct.sysctl_events_retry_timeout, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = proc_dointvec_jiffies, - }, {} }; #endif /* CONFIG_SYSCTL */ @@ -196,7 +272,6 @@ static int nf_conntrack_event_init_sysctl(struct net *net) goto out; table[0].data = &net->ct.sysctl_events; - table[1].data = &net->ct.sysctl_events_retry_timeout; /* Don't export sysctls to unprivileged users */ if (net->user_ns != &init_user_ns) @@ -238,12 +313,13 @@ static void nf_conntrack_event_fini_sysctl(struct net *net) int nf_conntrack_ecache_pernet_init(struct net *net) { net->ct.sysctl_events = nf_ct_events; - net->ct.sysctl_events_retry_timeout = nf_ct_events_retry_timeout; + INIT_DELAYED_WORK(&net->ct.ecache_dwork, ecache_work); return nf_conntrack_event_init_sysctl(net); } void nf_conntrack_ecache_pernet_fini(struct net *net) { + cancel_delayed_work_sync(&net->ct.ecache_dwork); nf_conntrack_event_fini_sysctl(net); } |